The overall objective of this project is to test the value of fluphenazine (FPZ) as a prophylactic medication in remitted schizophrenics, and secondarily to test whether there is a difference in this regard between oral fluphenazine and injectable fluphenazine decanoate. Two hundred patients will be randomly assigned to either placebo, oral fluphenazine or injectable fluphenazine decanoate and studied under double blind procedures for a period of 12 months. Our hypotheses are that maintenance medication will prevent relapses, and that injectable medication will be superior to oral because of the unreliability of many out-patients in taking medication.